Speed indicator and the like instrument



Dec. 7 1926. y A 1,609,400

A. M. COX

SPEED INDICATOR THE LIKE INSTRUMENT Filed Nov.

Dec. 7 1926.

. I 1,609,400 A. M. cox '1 SPEED INDICATOR AND THE LIKE INSTRUMENT v `Filed Nov. 5, 1923 6 Sheets-Sheet 2 F1431 y (sont) l Dec. 7 1926. 1,609,400

A. M. COX A SPEED INDICATOR ANDl THE 'LIKE INSTRUMENT I Filed Nov. 5, 192: e sneetssheet 5 A. M. cox

SPEED INDICATOR AND THE LIKE INSTRUMENT Filed Nov. 5, !9?C, 6 Sheets-Sheet 4 A. M. COX

SPEED INDICATOR AND THE LIKE INSTRUMENT- Filed Nov^ 5, 1923 6 Sheets-Sheet 5 Dec. 7 1926. I1,609,400 A. M. COX i SPEEDINDICATOR' AND THE LIKE INSTRUMENT Filed Nov` 5, l1923 6 Sheets-Sheet 6 Wwf/W02? Patented Dec. 7, 1926.

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ARTHUR MACDONALD COX, F EALING, ENGLAND.

`SPEED INDICATOR AND THE LIKE INSTRUMENT.

Application filed November v 1923. Serial No. 673,043, and in Great Britain November 6, 1922.

This invention relates to electrical speedometers, which, if desired, may be combined with an odometer dial and a total indicator.

One of the objects of the present invention is to provide a speedometer of which the power. for operating the same remains constant irrespective of the variation of the current or voltage utilized to ei'fect the operaf tion thereof. f

Another object of the invention is to provide an electromagnetic device for the operation of the speedometer which is simple in construction' and operation and which does not require any external source of current.

A further object of the invention is to prot vide aspeedometer which is capableof use for any length of time and of which the electrical actuating portion has no parts which are liable to fail during operation.

A still further object of the invention is to so arrange the armature, which actuates the indicating Vmechanism, that it drives the 1ndicating mechanism when operated mechanically whereas it is released from the actuating mechanism when attracted by its electromagnet.

These and other objects will be attained by the construction of a vspeedometer of which a preferred form will now be described with reference to the accompanying drawings, wherein:

Fig. 1 is a general front view of the mechanism.

Fig. 2 is a, side view partly in section of the same mechanism.

Figs. 3 and 4 are diagrammatic views of the chief parts of the movement.

Fig. 5 shows a detail connected with the click movement. l

Figs. 6 and 7 show twol views of an alternative construction of the movement.

Figs. 8, 9, 1 0 and 11 show details connected with magneto electric constructions kfor use on some rotary part, say the wheel,

of the car. t

Referring more particularly to Figs. 1 and 2 the instrument is mounted in a case 1 on which a dial 2, part only of which is seen, is mounted.

Inside the case I mount the electro-'magnet I 3 having poles 4Y and 5 between which is an armature' 6 pivoted at 7 and' carrying'an larm 8. The armature has limited rocking movement between the poles and a stop 9.

Attached to the pivot 7 is a spring 10 tending to keep the armature away from th-e poles. The tension of this spring can be adjusted as hereinafter described. The arm 8 carries a spring-controlled click 11 adapted to engage a ratchet wheel 12 on the spindle of a balance wheel 13 on which is also a pinion v14 in mesh with a toothed wheel 15, see Figs.

Upon momentary 'energizing of the magnet 8 the armature is rocked against the tension of spring and through arm 8 causes the click 11 to engage ratchet wheel 12. When cle-energizing occurs the spring 10 returns the arm 8 andcauses the click to drive the ratchet wheel 12 and the train of wheels through to the pointer. The movement of the click being continued until it frees itself from the ratchet wheel and permits the ratchet wheel and the train of wheels to return under the influence of the spring 16.

In its movements the click is controlled by a spring and suitable stops. A preferred method is that shown in Fig. 5 in which the click has a lug coacting with a face 26 on the end vof the arm 8. Spring 27 tends to bring the lug and the face together and hold the click in the position seen by dotted lines in Fig. 5. It will be noted from the construction that the click in its operative movement finally overruns and thereby -releases the ratchet wheel 12 which when released starts to return under the influence of the spring 16. On energizing of the electro-magnet, the click is also moved in this return direction, and during such return movement reengages by means of the spring 27 with the ratchet wheel and returns with the latter to the driving position. The click is thus placed in such relation to the ratchet as to again drive the latter on cessation of the electrical impulse. It'will be understood that the oscillations of the armature are rapid and as a result of this the engagements of the click in the ratchet wheel are such that it thrusts the said wheel around against the spring 16 until the tension ot the spring` is in balance with the speed of the click movements and the rotations ot' the train of Wheels is in equilibrium with the pointer over the appropriate position on the scale 2.

For odometer reading I mount a p'awl 30 on the arm S and cause it to drive a ratchet wheel 3l on the spindle ot which is a worm 32 adapted to drive worm wheel on spindle 34 furnished with a worm S13-adapted to rotate the odon'ieter dial 36. The spindle of the dial carries a worm 3T adapted to drive total indicator 3S through wheels 39, spindle --O and lWorm 41.

For the purpose ot' Zeroizing' the odometer 36 I provide a Aplunger 4t2 the inner end of 'which is connected to lever 48 pi-voted at iii anc. by which the 'tree end ot the lever can be pressed against spindles 410 and 3st thus removing wheel 39 and worm 35 trom'the dial 36 which is returned to zero by an overhung;y pin t5 and its springI 46. p

F or the purpose ot' adjusting; the instru- `meut to suit vdifferent vehicles it is only necessary to adjust the tension of the spring 10 and for this purpose Iv provide an eX- ternal screw a7 (Fig. 2) having' an eccentric pin i8 in engagement with a slot i9 in a lever through a hole in which the springl l0 is passed, see TEigs. 3 and It. l s In the modification shown in Figs. -G and T the armature is rocked as already described but its oscillations are conveyed through a toothed quadrant to a pinion 57 lined on spindle v58 which carries a vcoil or balance springv 59 lcoi'inected to balance wheel 60 on'spindle 6l which carries wheel 62 meshing witlrpinion 63 on the spindle Get of the pointer 65. Spring 66 is the equivalent ot l0 in its action on the armature.

In this .modification the quadrant 56 turns the balance wheel GO through the mediumot the spring'.` lt is assumed that the natural period of oscillation ot the balance Gdunder thev intluence ot the spring 5t) is considerably greater than the rate oit movement ot the quadrant. rlhe spring tendency is then to set the bai ance in position ot equilibrium with respect to the periods or' `HeXion and de-iiexion (reverse flexion) of the spring. In this modification the natural period of recoil ot the armature 55 under the influence of the spring 66 Visassumedto be inproportion to the number of oscillations of the armature in a given time.

And'it has been toundjthat with impulses ot' relatively short duration, the inertia oit the armaturewith respect to the strength of the recoil Vspringinay loe so arranged that, the, armature continuingits movement after cessation of impulse and recoiline; under effect otspring, will oscillate in a timerapproxiinately uniform, Awith respect to considerable variations .of 'amplitude and periodicity of impulse, so that ratio'of the More thanrone gapmay he used filled with non-1nagnetinc material.

:In ll a ,modiiication .is made in that the ring 73 has the bobbin v74 vlived adjacent its periphery instead of at the side as seen in Figstl to l0. v The ringi is'mounted on a 'nonmagnetic spider 75 rhaving` va split boss by' 'which it can be attached to a sha't't' or equivalent. ,A

l/Jhat I claim is: 'l

l. In 'aspeedometer7 an armaturepivoted intermediate its ends, an electromagnet inliuencingy the-respective ends ofthe armature in thesame rotative direction -to cause said armature to swing on its pivot, means t'or producing |`periodic electric impulses in said electromagnet, a springV strip secured to the armature in line with the .pivot and depending` below the same, means lfor fixing that end of the strip remote trom the armature against movement in response to armature movement, said spring being ten'sioned by ythe .movement of the armature in response `to the energization ot the electromagnet, van indicator, a y'balance,gear connected thereto, and means carried by the-armature to cooperate with and operate said gear in the n'iovement of the armature responsive to the tension of the spring strip following deenergization .of the electromagnet. 2. In a speedometer, an armature pivoted intermediate its ends, an electromagnet influencing the respective ends ot' the armature in lopposite directions to cause said armatureto swing on its pivot, means for producing periodic electric impulses in said electromagnema springstrip secured to the armature inline with the pivot and depending below the same, means 4for fixing that end .of thestrlp remote trom the armature against movement in response toarmature kmovement, said spring being tensioned by the movement ol. the armature in response to the enerdization of the electroma net van indicator, a balance gear connected thereto, an arm :rising .from ,the 'armature in line withftheppivot and a springjcontrolled click .carried @phy the larm and `vadapted to iengage andoperatesaid balance gear in those movements of .the armature responsive to the tension of the spring` strip.' y, H w

3. In a speedometer, an armature pivoted lli) armature to swing 4on its pivot, means forV producing periodic electric impulses in said electromagnet, a spring strip secured to the armature in line'with the pivot and depending below the same, means for iXing that end of the stripV remote from the armature against movement in response to armature movement, said spring being tensioned by the movement of the armature in response to the energization of theelectromagnet, an indicator, a balance gear connected thereto, an arm rising from the armature in line with the pivot and a spring controlled click carried by the arm and adapted to engage and operate said balance gear in those movements of the armature responsive to the tension of the spring strip, said click being mounted to remain in cooperation with the gear during the movement of the armature under the influence of the electromagnet. n

4. In a speed indicator of the character specified, an annular electromagnet, a pair of pole pieces secured one at each end of the electromagnet, means for imparting a series of electric impulses to the electromagnet, an armature pivotally mounted between said pole pieces and adapted to be attracted simultaneously `by both of said pole pieces when the electromagnet is energized, a limb secured to said armature, a spring actuated pawl mounted on said limb, a blade spring secured at one end to said limb, said spring being adapted to return the limb and armature to their normal position, a ratchet Wheel, the pawl being adapted to ride over said ratchet wheel without driving the same when the armature is attracted and to en-v gage with and positively drive 'said ratchet wheel when the armature is returned to its normal position by said spring so that the ratchet wheel will be driven by a uniform power at each operation of the limb and armature by the spring irrespective of the attraction exerted lon the armature by the pole pieces, a spindle. on which the ratchet wheel is mounted, a balance wheel and pinion on said spin-dle, a second spindle, a recoil spring, apinion and a toothed wheel on said second spindle, the toothed wheel gearing with the irst mentioned pinion, a third spindle, a toothed wheel mounted on said third spindle and gearing with the second mentioned pinion, a coil spring connecting the second mentioned toothed wheel to said third mentioned spindle, a balance wheel and a pinion on the third spindle, a fourth spindle,and a toothed wheel and a-pointer mounted on said fourth mentioned spindle, said third mentioned toothed wheel gearing with said third mentioned pinion.

5. A'speedometer including an indicator, a spring controlled gear connected thereto, an armature, an electromagnet for operating the armature in one direction, a spring for operating the armature in the other direction, and a click carried by the armature to cooperate withv the gear, said click operating the gear against its spring in those movements of the armature responsive to the spring strip, and means for supporting the click to cause the. same to automatically engage with the gear during the movements of the gear responsive to its spring and while the armature is being operated by the electromagnet. i

` In witness whereof l have hereunto set my hand. f

ARTHUR MACDONALD COX. 

